Provide Good Defaults PAGE 142
Show Only Valid Date Values PAGE 144
Minimize Clicks PAGE 146
Retain Customer-Entered Values PAGE 148
Consider if You Need Your Customers to Enter Dates PAGE 149
In contrast with the decimal Hindu-Arabic numeral system that was invented in India around 1,500 years ago, the Gregorian calendar has only been in use for approximately 428 years. As a consequence, humanity as a whole has had a bit less practice with calendars and dates than with numbers. Thus, date filters often cause even more usability issues than the numeric filters mentioned in the previous chapter, especially when they neglect basic design best practices. Dates are also among the most complex and time-consuming controls to manipulate: When asked to enter date values during usability tests, people often literally groan in pain. Yet many user interfaces stubbornly fail to safeguard customers from inadvertent errors and simply refuse to retain the calendar information customers so painstakingly provided. Sloppy or indifferent design of date filters can lead to unhappy customers. This chapter focuses specifically on date filters to show you how to design date filters that are as intuitive and pain free as possible.
For user interfaces, the initial impression is usually the most telling. Look at this government search interface from California's Department of Corporations Web site, pictured in Figure 9.1